All Pharmacy Pearls

Introduction

  • Ketamine is a sedative used for patients with extreme/refractory undifferentiated agitation
  • Indications for utilizing ketamine for emergent sedation of agitated patients include

    • a. Patient poses and immediate threat to patient and healthcare provider safety (RASS +4)

    b. Failure and/or futility of alternative non-pharmacologic de-escalation strategies

    c. Absence of IV access

    d. Not a candidate for intramuscular antipsychotics and/or benzodiazepines due to onset of action

Clinical Detail

    Properties

    Rapid acting general anesthetic producing cataleptic-like state due to antagonism of N-methyl-D-

    aspartate (NMDA) receptors in the central nervous system.

    • Ketamine also has significant analgesic/dissociative properties at lower doses

    Dose

    2-5 mg/kg IM to a max single dose of 500mg

    1-2 mg/kg IV

    Administration

    IM: Inject deep IM into large muscle (glute or vastus lateralis muscle)

    IV: Administer over at least 60 seconds

    Formulation

    10 mg/mL, 50 mg/mL, 100 mg/mL

    *must use 100 mg/mL for IM administration to reduce volume

    PK/PD (for

    amnestic effects)

    Onset: 3-5 mins IM; <1 minutes IV

    Duration: 15-25 mins IM; 5-10 minutes IV

    Bioavailability: 93% IM

    Metabolism: Extensively through hematic N-demethylation

    Elimination: Greater than 90% urine, <5% feces

    Adverse Effects

    • Hypertension

    • Tachycardia

    • Hypersalivation

    • Nausea and vomiting

    • Laryngospasm

    • Emergence phenomenon during

    recovery phase

    • Increased muscle function

    (hyperactivity, twitching, rigidity)

    Contraindications

    • Significant hypertension may be hazardous, ACS, ADHF, and unstable dysrhythmia

    Warnings and

Evidence

    Author, year

    Design

    (sample size)

    Intervention &

    Comparison

    Outcome

    Lin et al.,

    2020

    Prospective,

    randomized,

    pilot

    (n=93)

    Ketamine 4 mg/kg IM or 1 mg/kg IV

    Haloperidol 5-10 mg IM/IV +

    lorazepam 1-2 mg IM/IV

    Ketamine achieved greater sedation within 5

    and 15 minutes (22% vs 0% at 5 mins; 66% vs 7%

    at 15 mins)

    Mankowitz et

    al.,

    2018

    Systematic

    review

    (n=650)

    Ketamine IV or IM

  • Mean time to sedation was 7.21min and

    • effective in 68.5% of patients

  • 30.5% of patients required intubation, but not

    • all secondary to ketamine administration

    Cole et al.,

    2016

    Prehospital

    prospective,

    observational

    (n=146)

    Haloperidol 10 mg IM

    Ketamine 5 mg/kg IM

  • Median time to adequate sedation was faster

    • with ketamine (5 min) vs haloperidol (17 min)

  • Intubation rates were higher with ketamine

    • (39%) than haloperidol (4%), as well as more

    complications (49% vs 5%, respectively)

Conclusions

  • Ketamine has been shown to be effective with a quick time to sedation but is not without risks, including

    • respiratory depression

  • Used ketamine with caution in patients who have an underlying psychiatric disorder
  • Ketamine should be reserved for specific patient populations and as last line for patient/provider safety

References

    • Ketamine. Micromedex [Electronic version].

    • Lin M, et al. Am J Emerg Med. 2020. https://doi.org/10.1016/

    j.ajem.2020.04.013.

    • Mankowitz WL, et al. J Emerg Med. 2018;55(5):670-81.

    • Cole JB, et al. Clin Toxicol (Phila). 2016;54(7):556-562.

    • Isbister GK, et al. Ann Emerg Med. 2016;67(5):581-587.

    • Riddell J, et al. Am J Emerg Med. 2017.

    http://dx.doi.org/10.1016/j.ajem.2017.02.026

    • Scheppke KA, et al. WestJEM. 2014;15(7);736-41.

    • Barbic D, et al. Trials. 2018;19(1):651. Published 2018 Nov 26.

    doi:10.1186/s13063-018-2992-x

Tags:ketamine acute agitation midazolam emergence reaction

Source PDF

PFP – ketamine for acute agitation 6 – Copy.pdf